1 Plug in the device
Use a USB cable that supports data (not a charge-only cable). The board's red power LED should light up. On Windows you may also need the CP210x or CH340 driver, depending on your CYD variant — most modern Windows installs have it preinstalled.
2 Click below and pick your COM port
A browser dialog will ask you to choose a serial port — pick the one that appears when you plug the device in. If it doesn't show up, unplug and reconnect, or try a different cable.
Flash from a local build (advanced)
If you just ran pio run -e cyd on
this laptop, point the four file pickers below at
firmware/.pio/build/cyd/ and the framework's
boot_app0.bin. Nothing is uploaded to the server —
the installer streams the files straight from disk to the device
over USB.
.bin files here, or pick them individually:
pick 4 files to enable the local-build button
3 Wait for the install to finish
It takes about 30 seconds. The board will reboot
automatically and open a WiFi configuration portal called
FragmentChat-<chip-id>. Connect to it with your
phone to pick a network.
Troubleshooting
- "Failed to download manifest" — the server hasn't published a firmware build yet. Either publish one (instructions above), or use the local-build option.
- No device shown in the port picker — the port isn't being
recognized. Try a different USB cable (some are charge-only),
or install the
CP210x /
CH340
driver if you're on Windows. On Linux make sure your user is in
the
dialoutgroup:sudo usermod -aG dialout $USER+ relogin. - "Failed to connect to ESP32: Timed out waiting for packet header" — hold the BOOT button on the board while clicking flash, then release once connection is established.
- Chrome on Linux without Web Serial — use a recent Chromium build; Web Serial has been stable since Chrome 89.
- Want the full CLI workflow?
cd firmware && pio run -e cyd -t upload && pio device monitor